Overview of the development of quinolone resistance in <em>Salmonella</em> species in China, 2005&ndash;2016

Abstract

PurposeSeveral factors contribute to the complexity of quinolone resistance in Salmonella, including >2000 different Salmonella serotypes, a variety of hosts for Salmonella, and wide use of quinolones in human beings and animals. We thus aimed to obtain an overview of the development of quinolone resistance and relevant molecular mechanisms of such a resistance in Salmonella species.Materials and methodsA total of 1,776 Salmonella isolates were collected in Ningbo, China, between 2005 and 2016. Antimicrobial susceptibility to quinolone and relevant genetic mechanisms in these isolates were retrospectively analyzed.ResultsThe ratio for ciprofloxacin (CIP) resistant:reduced CIP susceptible:CIP susceptible was 26:522:1,228. CIP resistance was found in nine of 51 serotypes: Derby, London, Kentucky, Indiana, Corvallis, Rissen, Hadar, Typhimurium, and Agona. Of 26 CIP-resistant isolates, all were concurrently resistant to ampicillin and 21 were also concurrently resistant to cefotaxime and produced extended-spectrum β-lactamase (ESBL). The minimal inhibitory concentration values were at three levels: 2–4 μg/mL (serotypes except for Kentucky and Indiana), 16 μg/mL (one Kentucky isolate), and >32 μg/mL (Indiana isolates). As with the three most common serotypes, Salmonella Typhi showed quickly increased prevalence of reduced CIP susceptibility in recent years, Salmonella Enteritidis remained at a high prevalence of reduced CIP susceptibility throughout the study period, and several isolates of Salmonella Typhimurium were resistant to CIP. Transferable plasmid-mediated quinolone resistance gene qnrB was only found in all CIP-resistant isolates. In contrast, gyrA mutations were often found in reduced CIP-susceptible isolates and were not necessarily found in all CIP-resistant isolates.ConclusionWe conclude that in Salmonella, there exists a high prevalence of reduced CIP susceptibility and a low prevalence of CIP resistance, which focuses on several serotypes. Our study also demonstrates that, rather than gyrA mutations, qnrB is the most common indicator for CIP resistance.

<p>Expansion of <em>Salmonella </em>Typhi clonal lineages with ampicillin resistance and reduced ciprofloxacin susceptibility in Eastern China</p>

“…As showed in our previous study, this D87Y mutation was detected only in the S . Typhi with reduced ciprofloxacin susceptibility 17. The present findings concerning the reduced ciprofloxacin susceptibility are the same as that in Peru 15.…”

Evolution of Ciprofloxacin Resistance-Encoding Genetic Elements in Salmonella

“…Kentucky, and S . Typhimurium strains but not in other serotypes ( 7 , 25 – 27 ). Instead, PMQR genes, often in the form of multiple PMQR genes located in the chromosome and plasmids, now are commonly detectable in ciprofloxacin-resistant Salmonella strains of various serotypes.…”

“…Currently, target gene mutations, in particular single mutation in the gyrA gene, may be detected in S. Typhimurium but is rarely seen in other serotypes of Salmonella. Double mutations in gyrA and single mutation in parC that mediated high-level resistance were seen only in S. Indiana, S. Kentucky, and S. Typhimurium strains but not in other serotypes (7,(25)(26)(27). Instead, PMQR genes, often in the form of multiple PMQR genes located in the chromosome and plasmids, now are commonly detectable in ciprofloxacinresistant Salmonella strains of various serotypes.…”

Extended-Spectrum β-Lactamases in Human Isolates of Multidrug-Resistant Non-typhoidal Salmonella enterica

“…However, the emergence and spread of ESBL-producing NTSs as the result of the extensive use of cephalosporins has become a worldwide issue with serious consequences ( Philippon et al, 1989 ; Bradford, 2001 ; Zhao and Hu, 2013 ; WHO, 2017 ; Ur Rahman et al, 2018 ). Besides, the emergence of non-susceptibility to fluoroquinolones such as ciprofloxacin has been reported among NTSs over the recent decades ( Crump et al, 2015 ; Medalla et al, 2017 ; CDC, 2018 ; Song et al, 2018 ). In the WHO report on the global status of antimicrobial resistance (AMR) and surveillance ( WHO, 2014 ), fluoroquinolone-resistant NTSs were listed among bacteria, drug resistance of which is of international concern.…”

“…In the WHO report on the global status of antimicrobial resistance (AMR) and surveillance ( WHO, 2014 ), fluoroquinolone-resistant NTSs were listed among bacteria, drug resistance of which is of international concern. Moreover, control and treatment of salmonellosis is complicated by the dissemination of ESBL-producing strains, which could also acquire resistance to fluoroquinolones ( Wong et al, 2014 ; Crump et al, 2015 ; Song et al, 2018 ). Multidrug-resistance (MDR) of NTS strains to the first-line AMs necessitates the use of more toxic or last resort AMs, which is undesirable.…”